1. Field of the Invention
This invention relates to a vehicle classifying apparatus for classifying a vehicle passing therethrough and a toll system including the same for requesting a toll in accordance the class.
2. Description of the Prior Art
A vehicle classifying apparatus for classifying the vehicle passing the sensor with the velocity and three dimensional profile determined with pulsed laser beam is known.
The vehicle classifying apparatus is provided to on a highway at a toll gate to automatically issue a note representing the class of the vehicle or the like. Moreover, in the automatically tolling system, the class (type) of the vehicle is detected. Such a vehicle classifying apparatus is disclosed in U.S. Pat. No 5,546,188.
FIG. 49 is a perspective view of such a prior art vehicle classifying apparatus. A vehicle classifying unit 10 is provided to a beam of gantry 13 for each lane at a highway toll gate. The vehicle classifying unit 10 confronts the lane 11 and emits laser beams Xa and Xb in width direction of the lane 11 with a predetermined interval to provide scanning lines La and Lb.
The laser beams Xa and Xb are emitted as pulses. Delay between the emitting timing and the receiving timing is detected to measure a distance. When an object having a height passes therethrough, the detected distance varies, so that the vehicle passing therethrough can be detected. The speed of the vehicle 14 is detected from the detected time interval that a portion of the vehicle 14 passing through a distance 5. The length of the vehicle 14 is predicted from the detected time interval necessary for passage of the top to the end of the vehicle 14 and the detected speed.